AHMED AWAD ALDHAHRI

SUPERVISOR DR DARFIANA NUR

Meta-Analysis of a Systematic Review on Adult Obesity in

Kuwait

Background

Obesity has become a global issue due to associated health problems (Swinburn, et al, 2011).

Consistently increasing prevalence rates worldwide (Nguyen & El-Serag, 2010).

Linked with multiple health conditions and illnesses (Halfon, N, et al, 2012)

A leading factor for morbidity and mortality across the globe (Griffin, et al, 2013).

Background

Around one-third of the total world population is obese (Wang et al, 2008).

Other consequences associated include social, psychological and economic (Rofail, et al, 2013).

Projection of the future trends reports a continuous increase in obesity levels across countries (Wang, et al, 2011).

Kuwait being among the top list of countries with the highest obese population (Karageorgi et al, 2013).

Systematic Review: Karageorgi et al (2013)

Review the findings and methodology of studies on the prevalence, trends and risk factors of obesity in Kuwait.

A systematic review of relevant studies.Searched 111 cross-sectional – from 1997-

2002 – articles from the PubMed Database.Keywords: Obesity and Adults and Kuwait.111 articles reduced to 18 after being

filtered.

Systematic Review (Karageorgi et al ,2013)

Abstract and full-text reviews.Ranged from 177 to 3861 individuals.

Random sampling for 30% studies.Findings:

The prevalence (BMI ≥ 30) in studies with a nationally representative sample ranged from 24% to 48%

In adults > 50 years was greater than 52% Women were found to be more obese than men. An increase in trends of obesity was found from 1980 to

2009. Multiple risk factors were involved.

Objectives

To extend the existing systematic review in the literature using more databases until the end of 2014.

To conduct and exhaustive search and inclusion of obesity research in Kuwait.

To filter obesity research in literature related to important factors such as lifestyle and sociocultural

To implement meta analyses based on studies.

Meta analysis

What is a Meta-Analysis?A statistical technique used to integrate

findings from different studies.Generally used for evaluation of

effectiveness of healthcare interventions (Crombie, 2009).

Validity of meta-analysis quality of the systematic review.

Meta analysis

Fixed Effect Model Assumption: All included studies share a common effect size, µ. Observed Effects distributed about µ Variance σ2

Depends on the sample size for each study.

Random Effect Model Assumption: Instead of one single common effect size, it is

assumed that there is a distribution of true effect sizes. Representation of the mean of the population of true effects. True effect sizes θ are distributed about μ with a variance value of σ2 The observed effect T for any given θ will be distributed about that θ with a

variance σ2 that depends primarily on the sample size for that study

Borenstein, Hedges & Rothstein, 2007.

Meta analysis

Meta Analysis in RR is basically an open-source, and free statistical

environment.Runs on Windows, Mac OS, and Linux PlatformsComprises of 20+ packages of meta-analytic

packages on CRAN.Involves tools for meta-regression, multivariate

meta-analyses, and Bayesian meta-analysis.

Source: R-project.org, 2015

Research Timeline

Draft of Introduction (Chapter 1): End of October, 2015

Literature Review (Chapter 2): Mid of November, 2015

Systematic Review (Chapter 3) : End of January, 2016

Meta analysis (Chapter 4) : End of April, 2016Conclusion & Future Research (Chapter 5):

End of May, 2016Seminar : Mid of June, 2016Progress Presentation : End of June, 2016

References

Al-Kandari, Y. (2006). Prevalence of obesity in Kuwait and its relation to sociocultural variables. Obesity Reviews, 7(2), 147-154.

doi:10.1111/j.1467-789x.2006.00231.x

Borenstein, M., Hedges, L., & Rothstein, H. (2007). Meta-Analysis Fixed effect vs. random effects. Meta-analysis.com

Crombie, L. (2009). What is a Meta analysis. Sanofi-aventis.

Al Rashdan, I., & Al Nesef, Y. (2009). Prevalence of Overweight, Obesity, and Metabolic Syndrome Among Adult Kuwaitis: Results

From Community-based National Survey. Angiology, 61(1), 42-48. doi:10.1177/0003319709333226

Swinburn, B.A et al. (2011). The global obesity pandemic: shaped by global drivers and local environments. The Lancet. 378(9793)

Griffin, J.W. et al. (2013). Morbid obesity in total shoulder arthroplasty: risk, outcomes, and cost analysis. Journal of Shoulder and

Elbow Surgery. 23(10).

Ghazali, S. et al (2010). The Relationship between Lifestyle and Body Mass Index Among University Students in Kuwait. The

Egyptian Journal of Community Medicine. 28(1)

Nguyen, D.M., & El-serag, H.B., (2010). The Epidemiology of obesity. Gastroentorology Clinics of North America. 39(1).

Remington, et al. (2010). Chronic Disease Epidemiology and Control, American Public Health Association, Washington, DC, USA,

3rd edition, 2010.

Rofail, D., et al. (2013). A Review of the Social, Psychological, and Economic Burdens Experienced by People with Spina Bifida and

Their Caregivers. Neurology and Therapy. 2(1).

World Health Organization,. (2015). WHO | Obesity and overweight. Retrieved 16 September 2015, from

http://www.who.int/mediacentre/factsheets/fs311/en/

Wang, Y.C. et al, (2011). Health and economic burden of the projected obesity trends in the USA and the UK. The Lancet.

378(9793)